Customer service: +45 75 42 02 55
Danish design
Energy efficient and reusable radiators
Hudevad design radiator

Hudevad Radiator Guide

The easy to understand guide on how to order a radiator online.

For many, ordering a radiator online may seem like a complicated and big task, but it doesn't have to be difficult. In our radiator guide, we aim to guide you and give you answers to the most frequently asked questions in connection with ordering a radiator on our website.

First, we will give you a very quick overview of the words you will encounter when you order a radiator from us and why we would like to know. We give you links to more information, for those of you who want to know more - and then we have created a simple and clear step-by-step guide on how to find the right radiator size and radiator solution for your home.

Terms you will encounter

Tapping or connection

A tapping or connection is simply where the holes in the radiator are located and must be connected to the pipes in your heating system. A standard radiator is equipped with 4 taps (one in each corner of the radiator) and is the solution many people have in their homes.

At Hudevad, however, there are several options, as we can also supply the radiator with a built-in valve/valve insert, we can make it with extra tapping’s at the bottom if your radiator pipes come up through the floor or with completely hidden tapping’s where the pipes come out through the wall behind
the radiator.

When we ask you to specify which tapping you need, it is for us to know where the pipes need to be connected to the radiator.

Standard tapping
Bottom tapping
Hidden tapping

Well, where and how do I find out which tapping I need for my radiator, you might think!

The easiest is perhaps to look at the radiator that is already installed. Where does the hot water enter the radiator and where does the cold water exit? Most people replace their radiator with one with the same tapping’s as the one previously installed if the dimensions of the new one fits the piping. If you are about to install a brand-new radiator where one has not previously been installed, there is a little more leeway and here it is a good idea to ask your local installer for advice, as new pipes must be installed anyway. Maybe you can have the new pipes hidden in the wall so you can't see the pipes at all or maybe it makes more sense to have the pipes come through the floor.

All our products are equipped with what is called a tapping guide, so you can get an overview of the possible tapping’s/connections the individual radiator can be produced with. You can find the tapping guide here or when you are online it can be found on the product page, where you can click on the small i to display the possible tapping’s available on that radiator. Please note that not all radiators can be fitted with all types of tapping’s.


The type corresponds to how deep (and thus how big the output is) of the radiator and at Hudevad we work with the following types on our panel radiators:

Type 10 - 1 panel
Type 11 - 1 panel, 1 convector
Type 20 - 2 panels
Type 21 - 2 panels, 1 convector
Type 22 – 2 panels, 2 convectors
Type 33 – 3 panels, 3 convectors
Type 44 – 4 panels, 4 convectors

Hudevad panel radiator types

The following types are used on our model SC (column/element radiator):

Type 14 = SC, single, element distance 40 mm
Type 24 = SC, double, element distance 40 mm
Type 16 = SC, single, element distance 60 mm
Type 26 = SC, double, element distance 60 mm

When we ask for the type, it is to know how deep the radiator must be and how much heat/performance it must be able to produce. Please note that not all radiators can be made in all types.

The depth of the different types can be seen in the individual radiator's data sheet or in the specification. Please note both the depth of the radiator itself and the distance from the wall to the front of the radiator, as they can vary from type to type.

So how do you find which type of radiator you need? Again, it is a good idea to look at the radiators that are already installed in your home. If it heats the room sufficiently, it is most likely a type very similar that you need. Are you about to switch from district heating, gas boiler, oil boiler etc. to a heat pump or ground heating, you may need a larger radiator, as the temperature set (flow and return temperature) is lower.

If there is no radiator or you are about to change the heating system, it is a good idea to follow our simple step-by-step guide below to find the size of radiator you need. Please bear in mind that the below guide is only for guidance and that you should consult a heating engineer or installer if you have any doubts.

How to find the right radiator size

Step 1: Which heating system do you have?

Radiators are sized to be able to heat a room at an outside temperature of -4º C.

In the UK we typically use temperature sets as follows:

Old domestic heating boiler: 75/65/20
New installed domestic heating boiler: 55/45/20
Heat pumps: 55/45/20 (BS EN14511 specifies 45/40/20 test conditions at 7º C outdoor air temperature)
District heating: 70/50/20

The figures must be understood as: Flow temperature / Return temperature / Room temperature

Step 2: How big is your room?

Here you need to establish the volume of the room in which you wish to install your new radiator. This can be done by calculating the size of the room as below:

Length of room (m) x Width of room (m) x Height of room (m) = volume of room

This will tell you how much space that needs to be heated within that given room.


Length: 4 meters x Width: 3,7 meters x Height: 2,7 meters = 39,96 m3

Step 3: The Watt calculator

We use Watts to measure how much energy a radiator uses.

When you have calculated the volume of the room, the next step is to work out the amount of heat output needed for the room in Watts.

Room volume (m3) x 67

Please note that our Watt calculation is an estimate and that we recommend that you get professional advice from your installer.


Using the example above, we have a room with 39,96 m3 x 67 = 2677 Watts

It is important to calculate the correct number of Watts for your room, so it’s heated properly. If the Watt output is too small, your room will not get enough heat and on the other hand, if the output is too high, your room will be too warm, and you will then waste energy and thereby money.

Step 4: Adjust for room features

You now should have your required Watts for you room, but there are a few more factors that can either increase or decrease the Watts needed, like insulation, windows, if the room is below another room etc.

Here are some factors that all can influence the Watts and what you need to do about it

FactorWhat to do
Solid floor- 10% from Watts
If bedrooms upstairs- 25% from Watts
For foam filled cavity walls- 20% from Watts
For double glazing- 5% from Watts
For uninsulated cavity walls+ 10% to Watts
For two outside walls+ 15% to Watts
For three outside walls+ 40% to Watts
If room face north+ 10% to Watts
No loft insulation+ 15% to Watts
Extra high ceiling (over 3 meter)+ 20% to Watts


If we use our previous example, we have a room where we need 2677 Watts
This room have a solid floor= - 10 % (2409 Watts)
There is a bedroom upstairs= - 25 % (2008 Watts)
It has 2 outside walls= + 15 % (3079 Watts)
It faces north= + 10 % (3387 Watts)
Required Watts is now= 3387 Watts


You now know that you room requires 3387 Watts of output to heat the room and whether you want one large radiator, 2 smaller ones or 3 small ones is entirely up to you. Your aim is a total output of approx. 3387 Watts.

Step 5: Which radiator should you choose?

This is where it gets a little more exciting, because now you must choose the radiator model or type you would like to install in your room. If you already have a radiator you'd like to replace, it's simple. You can just look for a radiator of the same size as the one you have or that at least fits the pipework in your house and check that the radiator's output matches the heating needs of the room.

If you don't have a radiator, you have a bit more freedom in terms of design, pipework etc. What style are you after? Do you want a large radiator as a statement piece on the wall? Or a narrow vertical radiator to save wall space? Or do you have large window section where you would rather not block the view and therefore need to use low Lowline radiators? We know it can be difficult to choose, and we have therefore collected all our radiators in a simple Hudevad Design Guide, where we have described the characteristics, appearance, etc. of our various radiators. It can be downloaded right HERE. Look at it when you have time and continue below with step 6.

Step 6: Where do I find the output/Watts of the radiator?

Under Downloads or on the individual product pages here on the Hudevad website, you can find our conversion sheets or output calculations. A radiator output calculation shows you the heat output of the different sizes of a given radiator. At the very top of our output tables, you must first type the temperature set you have noted under Step 1, which your heating system is based on. Secondly you can type in the Preferred output W in the green section. When you scroll down, all the radiators sizes that fulfill your requirements will now be marked with green.

Now all that’s left to do, is find the radiator type and size that best suits your heating needs.

In short:

1. Which heating system
2. The size of the room
3. Watts calculation
4. Adjust for room features
5. Which radiator
6. Find the output

What else could I need for my radiator?

Thermostats and valves

Please note that the valve and thermostat is not supplied with the radiator. This should be ordered separately.

Our radiators come with an air valve and bleed valve as standard. In addition, you can order a thermostat and valve, which are used to regulate the room temperature and provide an efficient and comfortable heating. We have a large selection of both mechanical and electronic thermostats that all ensure a comfortable indoor temperature.


You might also need fittings, such as angle fittings, connection fittings etc. for your radiator installation. It might be a good idea to ask your installer what is needed, or he can supply the parts you need.


If the radiator is to be placed where wall space is limited – perhaps even in front of a window – most of our radiators can be mounted on feet. This gives you a more freedom in your interior design, but of course you still must remember that the radiator needs pipework.

Colored radiators

Maybe you want your radiator in a different colour? Maybe you want to highlight it, or you want it to "blend in" with the wall? We can supply all our radiators in all ​​RAL Classic colours, and you can read much more about colours and the effect they have on interior design, our mood and much more in our colour brochure.  You cannot order colored radiators online, but you are always welcome to contact us if you want a radiator in a different color or gloss. We will try our utmost to assist you.

If you have more questions, many of them can probably be answered in our FAQ section. Otherwise, you are always welcome to contact us with your question and we will do our best to help you.


We have made an big radiator guide for you to download.  In here you will find all relevante information on a radiator from Hudevad such as special installations, what you need to consider if you cover up your radiator, noises from the radiator or heating system and much, much more. 

Download the brochure
Back to Top